
248 THE NORTHERN MICROSCOPIST. 
its tube or sheath in one of the depressions of the empty egg-case. 
Unfortunately the glass of the polype-trough was too thick to use 
the 4-inch objective, therefore we used the }-inch objective and D 
eyepiece ; a power which was insufficient to enable me to make an 
elaborate investigation. I have the creature still by me, but it is 
either dead, or encysted, as it has for some time past refused to 
come out of its tube. The genus appears to be so little known 
that it would perhaps be advisable to quote Prichard’s description. 
Family Vorticellina. “ Genus Chetospira (Lachmann).—The sur- 
face generally covered with cilia, like the genus Stentor, from which 
it is distinguished by having that part of the parenchyma of the 
body which bears the ciliary spiral and the anus (which in all the 
Stentorinz lies on the dorsal surface of the body, close under the 
ciliary spiral, and not in a common pit with the mouth) drawn out 
into a thin process. This process is narrow and bacillar ; the series 
of cilia commences at its free extremity, and only forms a spiral 
when in action, by the rolling-up of the lamina. The process 
bears the anus. The animalcules inhabit a sheath or tube, of 
a mucilaginous or even horny density.” The genus was first 
described in 1856 by Mr. Lachmann, who found the two species of 
which it consists in fresh water near Berlin. ‘They are described 
by Prichard as follows :— 
“ Chatospira Miilleri—Slender. The first cilia of the series upon the process 
are somewhat, but not remarkably longer and stronger than the rest ; when rolled 
up, the ciliated bacillar process forms more than one turn of a spiral. Sheath 
flask-shaped and horny. Hitherto found only in the open cells of torn leaves of 
Lemna trisulca, growing in fresh water near Berlin.” 
“ Chetospira mucicola.—Enclosing tube mucous in consistence; animalcule 
shorter and more compressed ; the rolled-up ciliary process does not form a 
complete turn of a spiral ; the first cilia are considerably larger than the rest, the 
first one especially being nearly twice as long as most of the others.” 
The animalcule we found does not altogether agree with either 
of these descriptions. It has, like Chetospira Miilleri, a horny 
sheath, to which are attached a great number of brown granular 
particles, as though they had been cemented to it. ‘The case is not 
imbedded in, but built outside the cellular substance to which it 
adheres. ‘The ciliary process resembles C. mucicola in not making 
a complete turn of a spiral. At the extremity of the process there 
appeared to be a small projection as though it hada slight tendency 
to be bilobed, like the allied genus “vera, but the animalcule main- 
tained a very awkward position all the time we watched, so that it 
was impossible to get a clear view of it; therefore it is just pos- 
sible that this appearance was due to a distorted view of the long 
terminal cilium characterising C. mucicola. On giving the stage of 
the microscope a sharp tap it would quickly withdraw within its 
tube, after the manner of Vaginico/a and other sheathed animalcules; 
as soon as its alarm subsided, the process would be slowly extruded 

